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The Appareil Respiratoire Tissot Mle.1916 and Appareil Respiratoire Tissot Mle.1917, also known as the French Tissot Mask was the first gas mask to incorporate the "Tissot Principle".

Early Development[]

Dr. Jules Tissot, who lived from February 17, 1870 to June 17, 1950, was a French Biologist who had experience developing Spirometer equipment for the medical field in 1904 as well as being the inventor of an oxygen breathing apparatus designed for mine rescue in 1907. The French Government acquired devices towards the end of April 1915, they were to be used by the French Military. In its entirety, 250 Mine Rescue Apparatus's were manufactured. On April 22nd of 1915, after the appearance of poison gas in armed conflict, Dr. Tissot initiated research on the manufacture a new apparatus for protection against gases.

Dr. Tissot developed a prototype that was eventually sent to a committee that organized and conducted a test which would evaluate the capabilities of the apparatus, this would take place at Lebeau Laboratory on January 8, 1916. The test subject entered the test chamber filled with benzyl bromide and phosgene gases. The test subject was observed as gas was gradually added to the atmosphere of the chamber. After 20 minutes, feeling a slight tingling in the eyes, the test subject exited the room and the test was concluded.

Six days later, January 14th, a second test at Satory, this time, the test was outdoors and Dr. Tissot was invited. The purpose of this test was to have the test subject traverse through clouds of phosgene, chlorine, and arsine smoke gases, beginning 50 meters from the gas canisters. Both Tissot's mask and the older TN mask would tested during this experiment, they would also be timed how long they could go without feeling the effects of the chemical agents.

The Tissot apparatus was ruled as the superior mask upon completion of the testing, the committee proposed to continue the development of the Tissot Apparatus, not to substitute for the other masks in service, but to replace the Draeger Rebreather and other oxygen breathing apparatus's. The main disadvantage of these older masks was the period of use, which could not exceed half an hour. In contrast, The Tissot Apparatus, extensive tests was determined that in light gas concentrations, the device could work up to 50 hours before being exhausted, and 30 hours in extremely heavy gas concentrations. At the time, the Tissot Apparatus protected against all period-used chemical warfare gases, unlike some of the older masks which may only protect against a specific chemical agent.

The Committee decided to produce 1,000 units initially to continue research in order to develop a production model. On April 29, 1916, testing was completed. To that date, 450 Tissot masks had been manufactured and 50 had been tested by a company that produced toxic gases. Unanimously, the Tissot apparatus was chosen and adopted into military service. Delivery of the masks to the front lines started that same year in the month of July.

Facepiece Overview[]

The Tissot Principle[]

Dr. Tissot had sought to avoid fogging on the lens of the eyepiece glass, he thought he could do this by cooling the inside of the lens. He developed a system in which the air that entered the mask while inhaling fresh air would travel through tubes and end up right at the eyepieces. This would ensure that were repeatedly exposed to colder air, which was cooler than the air inside, which prevented condensation. Similar systems were already in use for commercial diving helmets at the time, however, Dr. Tissot's mask was the first air-purifying respirator to utilize such a system.

Characteristics[]

The entire mask, including the head harness, was made of either black or grey, 'cold-vulcanized' gum rubber. The glass eyepieces were attached to the mask with reverse-crimped metal rings, and the air inlet/outlet angletube system consisted of 'horizon blue'-painted copper/brass tubing that housed the hose connector and the outlet valve.

As stated before, the clarity of vision was improved by the tubes that would route air up to the glass eyepieces, later, it would be called Tissot tubes. These two tubes were made of rubber and were connected from the bottom of the lenses to a pipe that lead to the hose. Metal insert ferrules were inserted in the eyepiece tube connections to prevent the collapse of the rubber tubing.

Exhaling was made possible through a metal check valve that was located directly on the mask on a pipe angled upwards to prevent damage and blockage from debris. The intake tubes were soldered to this angled assembly. Inside the mask, there was a folded wire spacer with rubber tube padding connected to the outlet port in the mask that prevented the collapse of the mask upon inhaling.

Improvements[]

By the end of 1916, a rubber flutter valve was added to the metal check valve assembly to prevent it from being clogged with debris or flooded by rainfall. Another development was made in late 1917 - The mask's gum-rubber facepiece tended to tear after a short period of time, so some copies would be manufactured in the same way as the ARS-17 Mask. The upgraded facepiece came in 3 sizes and was constructed of a rubberized-fabric-impregnated rubber facepiece with boiled linseed oil. This provided extra protection because it was twice the thickness of the original gum rubber facepiece.

Filter Units[]

Large (Grand) Model[]

In its first rendition, filtration was carried out by a rectangular, backpack-sized, gray-painted metal box containing two layers of filtering materials: two layers of steel wool saturated with a sodium hydroxide solution and a second layer consisting of wood chips soaked mixture of castor oil and sodium bicarbonate. The canister was carried on the back due to its large size, this was accomplished by a harness made out of waxed cord, on top of it, there were threads that allowed the non-corrugated hose to be connected to this filter and to the facepiece. On the bottom, there was an air intake port with a rubber inhalation valve and a rubber plug to seal the canister when not in use.

An additional cartridge containing castor oil-impregnated sawdust was also added and connected under the canister at the inlet port. This smaller, auxiliary cartridge was threaded on the upper side and had a cap with a bayonet latch closure on the bottom to seal it. This smaller auxiliary filter allowed additional protection against arsine smokes. However, it needed to be soaked for 5 minutes in water before use to moisten the chemicals impregnated in the sawdust to activate them, and thus the castor/sawdust filling was replaced with charcoal by August of 1916.

Additionally, the castor oil-soaked wood chips of the main canister were replaced with charcoal as well between August of 1916 and March 10, 1917. The new new canisters had a yellow star stamp, while older canisters had a black star marking. The charcoal-filled 'Yellow Star' Large Model Canister began to appear on the battlefield at the end of June 1917, where it was soon learned the charcoal, which still needed moistening for arsine protection, would quickly dry up. This was later replaced with a pre-soaked charcoal mix in August of 1917. The auxiliary smoke canisters containing the new charcoal were threaded on both ends and were painted entirely yellow to distinguish them from the earlier smoke canisters.

Between January and Summer of 1918, the sodium hydroxide + steel wool layers of the main canister were replaced with granulated soda lime to avoid severe chemical burns to the user when the solution is inadvertently inhaled into the facepiece from the steel wool. After this incident, to warn others of the dangerous old filters, the models containing the caustic soda/steel wool layers were marked with the inscription: "Don't forget to purge the canister after each use to prevent the flow of clothes-burning liquid". More than 100,000 units of the Grand Model Tissot were manufactured until the Armistice was declared in 1918.

Small (Petit) Model[]

Despite the superior protection, the Grand Model Tissot proved to be too heavy, large and uncomfortable, so in November 1916, development on a smaller, and lighter canister began. On December 2, 1916, the canister was finalized as the 'Petit' Model and was comprised of seven layers Sodium Hydroxide impregnated gauze with a layer of activated charcoal retained between two wire mesh screens packed by springs.

The filter was able to provide protection against most agents of era until the introduction of German arsines in the Summer of 1917. Diphenylchloroarsine could penetrate the gauze layers and the charcoal layer. It was determined that only cotton was capable of stopping this substance, so an additional auxiliary smoke canister, containing the hydrophilic cotton was developed and was issued in late 1918. Unlike the Grand Model Canisters, which were cylindrical, the Petit Model Smoke Canister was rectangular in shape with the same diameter of the main canister body and was fixed in place with two cotton straps that were a part of the main canister's harness. This canister was marked with red paint on the top.

Much like the Grand Model Canisters, the Petit Models replaced the caustic soda + steel wool wet filter layer with granulated soda lime in the Summer of 1918. The new soda lime petit canisters were distinguished from the former caustic soda models by the lack of drain holes at their base and they did not have a red band of paint. More than 590,000 units of the Petit Model Tissot were manufactured until the Armistice was declared in 1918.

Kit[]

The mask comes in a large rectangular wooden box painted 'horizon' blue with large black markings that read: "APPAREIL T" (Apparatus Tissot) to indicate what was contained within because it was not intended to be worn by a regular infantryman or soldier who needs to move from place to place constantly. It was considered a special sector apparatus that remained in place in a fixed position like its user (e.g. machine gunners, artillerymen, snipers, communications troops and combat engineers).

Success of the Petit Model and American Testing[]

In October 1918, it was decided to permanently replace the Grand Model Tissot with the Petit Model. By this date, all manufacturing had stopped due to the end of the war. During mid-1917, U.S. Army would procure several specimens of the Appareil Respiratoire Tissot Mle.1917 for testing and evaluation, with some even seeing service with the AEF with Medical and Signal Corps personnel.

Surviving Samples[]

Almost no examples of this mask survive. After almost 100 years since it was last manufactured, most Tissot masks have been lost to old age and due to the period materials not being as resilient to aging as today's synthetic rubbers. A Petit Model filter, angletube, chin rest, canister, and smoke canister without a facepiece were once in the possession of a collector named Boris Plotnikoff, but since his passing, it is currently unknown where the specimen is. A postwar Fernez-Tissot Industrial Mask is currently owned by Artist Viktor Ferrando. A Petit Model canister resides at the National World War I Museum in Kansas City, MO.

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